When rain water is collected, it is usually directed to small lakes or retention ponds that may serve as water supplies or recreational cites for a local populous. Before the water empties into the lakes or ponds, it undergoes a filtration process. Water is usually collected in canals or ditches where in a filtration system separates and removes larger debris from the water. The bottom of the canal or ditch is lined with a multi-layered filtration bed. As the water drains into the ditch, it seeps through the bed and collects in a conduit system which directs the water to a second filtration phase.
A drainage bed may consist of a sand aggregate bottom layer, and consecutive stone layers of differing gradations on top of the sand bed. Deposition of such a multi-layered filtration bed usually requires depositing one layer at a time. Each layer is first deposited in the canal ditch then graded to a desired level. After grading to a desired level, another aggregate layer of a different gradation is placed on top of the first and also graded to a desired level.
It is an objective of the present invention to provide an aggregate extruder that simultaneously deposits multiple layers of different aggregates as it moves along a desire path. Still another object of this invention is to provide the extruder with a grading means that grades each layer as it is deposited. Yet another object of this invention is to provide such an aggregate extruder with self-propulsion means.
These and other objectives are achieved by utilizing a self-propelled extruder for simultaneously depositing and grading multiple sections of a drainage/filtration bed. The extruder includes a hopper divided into dispenser sections. Each section of the hopper is filled with appropriate aggregate material to be deposited to form the bed. A grading blade is mounted toward the rear of each dispenser section for grading the layer of aggregate deposited. A panel extends horizontally from each side of the rear of the extruder to maintain the width of the bed in that area behind the extruder. Wheels are mounted to the hopper to facilitate movement along a desired path.
A hydraulic system including a cylinder and rod extension is mounted on each side of the hopper. When the hydraulic system is activated, the arm extends from the cylinder and pushes against a fixed abutment forcing the hopper along the ditch opposite the extension of the hydraulic arm. As the hopper moves along the ditch or desired path, it deposits aggregate from each section of the hopper. The grading blade at the rear of each section grades the aggregate material deposited immediately forward the blade. An adjacent dispenser section is behind a forward section simultaneously deposits a layer of aggregate on top of the aggregate layer before it.